Amazfit GTS WatchFaces - Amazfit GTS WatchFaces is an app that allows you to access new and beautiful watch faces for your smartphones.
Wear Gesture Launcher - Wear Gesture Launcher – Wear OS – Wear Launcher that lets you forget about swiping that long of small icons, just tap, draw, and do.
Huawei Wear - Huawei Wear is an application that allows you to manage your Huawei smartwatch no matter what model it is, i.e., Huawei Watch, Huawei fit, and Huawei talk band wristbands.
wasp-os - Firmware for smart watches based on the nRF52 family of microcontrollers (including Pine64 PineTime)
Mi Heart rate - Continuous HR and smart alarm
InfiniTime - InfiniTime is an open-source, C++-based firmware OS specifically made for the PineTime smartwatch.